Normally, you would expect a wall, even one that runs for league, to follow the contours of the land and take advantage of streams and rivers in its defense. The great wall of Nevrinheer does not, it runs in a vague arc, over hills and across streams, without adjusting to the terrain, it simply is, a long wall to keep out an enemy that long longer exists from a land that the builders of the wall no longer occupy.
the Great Wall of Nevrinheer
The wall is surprisingly uniform, a seven foot (2m) deep and ten foot (3m) wide trench, often overgrown, behind which is an eighteen foot (6m) turf wall, faced with stone and topped with a stone wall with crenelations. The wall is fifteen feet (5m) thick at the base narrowing to ten feet (3m) at the top, which is laid with gravel and stone to make travel along it easier. But there are no towers, forts or barracks attached to the wall. It is just a wall, running the length of the land. It is often used as a high road by those who live near to it.